Cult of personality much? Don't get me wrong, Carmack is one of a kind. But seriously, "if Carmack doesn't understand your idea => your idea is hopeless" -- this can not be healthy.

EDIT: I'll elaborate a bit. In my experience in both industry and academia I've witnessed numerous occasions when brilliant people would get things wrong, ignore a brilliant idea, follow a hopeless research direction, etc. etc. Authority matters, but _nobody_ is flawless.